Nemaline myopathy in a six-month-old Pomeranian dog.

ABSTRACT: Nemaline myopathy - a clinically and genetically complex heterogenous group of disorders - is described uncommonly in humans and rarely in animals, and is characterised by progressive muscle weakness. The diagnosis is confirmed by histological and/or ultrastructural identification of subsarcolemmal, thread-like, rod-shaped structures called nemaline rod bodies within more than 40% of skeletal muscle fibres. These rods contain the Z-line protein, α-actinin, that can be effectively stained in skeletal muscles using Gomori or Masson trichrome and negatively stained with periodic acid-Schiff. Similar rod-like bodies have been found in smaller numbers in dogs with endocrine disorders and occasionally in other conditions in humans. This report is of a six-monthold Pomeranian dog which had progressive exercise intolerance over a two-month period associated with severe disuse muscle atrophy of the thoracic limbs, as well as gradual pelvic limb weakness and regurgitation of food. Baseline diagnostics ruled out endocrinopathies and after histological and ultrastructural evaluation of thoracic limb muscles and nerve biopsies confirmed nemaline myopathy. The clinical course, diagnostic test results, ultrastructure of skeletal muscle and peripheral nerve, gross necropsy findings and histopathology using various stains are described and illustrated.

Biodistribution and tolerance of intravenous iodine-131-labelled hypericin in healthy dogs.

Hypericin (Hyp) is a necrosis-avid compound that can be efficiently labelled with radioiodine for both diagnostic and therapeutic purposes. Before 131 I-Hyp can be considered as a clinically useful drug in a combination therapy for canine cancer patients, evaluation of its toxicity is necessary. The aim of this study was to investigate the biodistribution and tolerance of a single dose administration of 131 I-Hyp. Three healthy dogs were included. 131 I-Hyp at a dose of 0.2 mg/kg and an activity of 185 MBq was intravenously injected. The effects on physical, haematological and biochemical parameters were characterized and the biodistribution and elimination pattern, the effective half-life and dose rate were assessed. Drug-related adverse events were limited to mild gastrointestinal signs, resolving within 48 hours. No significant differences were found in blood haematology and serum biochemistry before and after treatment. Following administration, highest percentage of injected dose (%ID ± SD) was found in the liver (5.5 ± 0.33), the lungs (4.17 ± 0.14) and the heart (3.11 ± 0.78). After 24 hours, highest %ID was found in colon (4.25 ± 1.45) and liver (3.45 ± 0.60). Clearance from all organs was effective within 7 days. Effective half-life was established at 80 hours, and the dose rate fell below <20 µSv/h at 1 m within 1 day. The current study reveals that single dose treatment with 131 I-Hyp at the described dose is well tolerated by healthy dogs and supports the use of radioiodinated hypericin in a combination therapy for canine cancer patients.

The comparative biomechanics of the reinforced interdental crossover and the Stout loop composite splints for mandibular fracture repair in dogs.

OBJECTIVES: To describe a new technique, the reinforced interdental crossover composite splint (RIC), for transverse mandibular fracture repair in dogs. This technique was compared biomechanically with the established reinforced interdental Stout loop composite splint (RIS) technique. METHODS: Six pairs of mandibles from young adult small breed dogs were used for the study. Osteotomies were created in a standardized fashion and fixed with either RIC or RIS. All composite splint constructs were tested biomechanically with a cantilever bending force, using a single column testing machine at a rate of 2 mm/min. The time of application, amount of composite used, ultimate force, stiffness, total displacement, and total energy absorbed during displacement of the rostral mandibular segment were calculated and compared between the two groups. RESULTS: No significant difference was found when comparing the time of application of the RIC and the RIS techniques. All implants failed by either composite resin fracture over the region of the osteotomy or by fracture between the first and second molar followed by detachment of the resin from the lingual enamel surface of the first molar. Differences between the RIC and RIS in force (80.5 N ± 40.3 and 51.8 N ± 27.4. respectively) and stiffness (16.2 N/mm ± 4.4 and 10.1 N/mm ± 4.1 respectively) were significant (p = 0.03). However differences between the two techniques in displacement and total energy absorbed were not significant. CLINICAL SIGNIFICANCE: In experimentally fractured mandibles of young adult dogs there is evidence that RIC is biomechanically similar to RIS.

A retrospective study of 109 dogs with mandibular fractures.

OBJECTIVE: To determine patient factors and fracture morphology of dogs presented with mandibular fractures to a small animal referral centre in South Africa. METHODS: Patient data on age, sex, breed and aetiology of dogs with mandibular fractures were recorded. The fractures were classified according to the anatomical location, displacement, fracture type, fracture line direction, periodontal pathology, and whether there were teeth in the fracture line or not by evaluation of preoperative radiographs. Clinical observations indicated whether these fractures were open or closed. RESULTS: In total, 109 dogs with 135 mandibular fractures were included in the study. Small breed dogs and dogs less than eight months of age predominated (102/109). Dog fights were the most common aetiology in this study (68/109). The molar region was the most commonly affected region (56/135). Evaluation of the radiographs revealed that transverse (73/135), relatively unstable (116/135), and displaced (112/135) fractures were the most common. The majority of fractures involved teeth in the fracture line (100/135), with the first molar frequently involved (54/135). The majority of fractures were open (104/135). CLINICAL SIGNIFICANCE: The results obtained from this study may be used to guide patient and fracture morphology selection in biomechanical studies of mandibular fracture repair techniques. Screening of this patient population may inspire the search for new treatment options for mandibular fracture repair in South Africa.

Bilateral multiple cystic kidney disease and renal cortical abscess in a Boerboel.

Cystic renal disease is rare in dogs and although infected renal cysts have been reported in humans, no report could be found in dogs. A 58 kg, 5-year-old, castrated, male Boerboel presented with weight loss, pyrexia, lethargy and vomiting, 20 months after an incident of haematuria was reported. The initial ultrasonographic diagnosis was bilateral multiple renal cysts of unknown aetiology. The cysts had significantly increased in size over the 20-month period and some contained echogenic specks which could be related to infection, normal cellular debris or haemorrhage. In both kidneys the renal contours were distorted (the left more than the right). The abnormal shape of the left kidney was largely due to multiple cysts and a large crescent-shaped septate mass on the cranial pole of the kidney. Aspirates of the septate mass were performed (left kidney) and the cytology and culture were indicative of an abscess. It is suggested that the previous incident of haematuria provided a portal of entry for bacteria into the cysts resulting in renal cortical abscess formation.

Serial plasma glucose changes in dogs suffering from severe dog bite wounds.

The objective of this study was to describe the changes in plasma glucose concentration in 20 severely injured dogs suffering from dog bite wounds over a period of 72 hours from the initiation of trauma. Historical, signalment, clinical and haematological factors were investigated for their possible effect on plasma glucose concentration. Haematology was repeated every 24 hours and plasma glucose concentrations were measured at 8-hourly intervals post-trauma. On admission, 1 dog was hypoglycaemic, 8 were normoglycaemic and 11 were hyperglycaemic. No dogs showed hypoglycaemia at any other stage during the study period. The median blood glucose concentrations at each of the 10 collection points, excluding the 56-hour and 64-hour collection points, were in the hyperglycaemic range (5.8- 6.2 mmol/l). Puppies and thin dogs had significantly higher median plasma glucose concentrations than adult and fat dogs respectively (P < 0.05 for both). Fifteen dogs survived the 72-hour study period. Overall 13 dogs (81.3 %) made a full recovery after treatment. Three of 4 dogs that presented in a collapsed state died, whereas all dogs admitted as merely depressed or alert survived (P = 0.004). The high incidence of hyperglycaemia can possibly be explained by the "diabetes of injury" phenomenon. However, hyperglycaemia in this group of dogs was marginal and potential benefits of insulin therapy are unlikely to outweigh the risk of adverse effects such as hypoglycaemia.

Infiltrative angiolipoma of the parotid salivary gland in a dog.

Solitary benign angiolipoma and infiltrative angiolipoma are rare tumours in dogs. Angiolipomata can be distinguished histologically from lipomata by the large number of tightly packed blood vessels seen between the adipocytes with multiple fibrin thrombi occupying some of the vessels' lumens. The dog presented with a solitary slow-growing mass in the cervical region. Histopathology revealed multifocal to coalescing single or clusters of blood-filled vessels lined by flattened endothelial cells with narrow, elongated, basophilic nuclei. These regions were embedded in adipose tissue with multifocal areas of intervascular remnants of differentiated serous salivary glandular tissue with multifocal small ducts. Fibrin thrombi occupied a few of the vessel lumens. A histological diagnosis of infiltrative angiolipoma was made. On computed tomography, the mass was bilobed with a suspected primary component involving the right parotid gland which was grossly enlarged. The mass had a slightly hypoattenuating mottled to lobulated appearance with a few hyperattenuating mineralised specks throughout. Hounsfield units of the mass ranged between 40 and 45, which was less than the 60-65 of the contralateral salivary glands and cranial musculature. Post contrast images showed no contrast enhancement of 90% of the mass with only a band of peripheral contrast uptake of the affected lateral lobe.